Merkava Mk.3 main battle tank is a further development of the Merkava Mk.1 and Mk.2 main battle tanks that entered service in 1979 and 1983 respectively. Production of the Mk.3 began in 1990 an currently it is the primary battle tank of the Israel defence forces.

The Merkava Mk.3 had a number of improvements comparing with the Mk.2. The main features a more powerful main gun, improved modular armored protection, uprated engine, improved transmission and suspension.

Modular armored protection elements can be be easily replaced after direct hit by an anti-tank round or an RPG. Furthermore such arrangement allows to improved tank's protection with more advanced armor elements as they are available, or in case the tank becomes out-dated, new armor could greatly improve it's capabilities. Forward area of the tank carries additional armored plates to protect it's crew from the latest anti-tank weapons.

The Mk.3 has a completely new turret, housing a 120-mm smoothbore gun. This gun received a thermal sleeve which helps to increase accuracy by minimizing distortion caused by barrel overheating and weather conditions. This gun can fire anti-tank guided missile in the same way as the ordinary rounds. It carries 50 rounds of ammunition. Another feature of this MBT is when the ammunition is unloaded it's internal volume can be used to carry troops. This feature is unique in the tank building history and allows to use Merkavas as a heavily protected infantry fighting vehicles.

Additional armament consists from three 7.62-mm machine guns. One of them is coaxial with the main gun, while the other two are roof mounted. This MBT carries an impressive 10 000 rounds of 7.62-mm ammunition for it's machine guns. It is also completed with a 60-mm mortar used to fire illumination bombs at night and explosive rounds to defend from enemy infantry. Mortar is loaded aimed and fired from the inside of the turret.

Currently Israel defence forces operate approximately 1 200 Merkava Mk.3 and Mk.2 main battle tanks, however even more advanced Merkava Mk.4 had been developed and is already being delivered to the units.